The aptly named icanstalku.com attempts to expose the dangers inherent in posting information — in this case pictures — online in a rather unconventional way: the site regularly updates its news feed with individuals’ user names and locations, all gleaned from photos posted to Twitter.

The authors offer a detailed explanation, but the short answer is smart phones. Many of these mobile devices are equipped with GPS and other capabilities, which they use to add metadata (information about your information) to your photos. This includes information like when and where the photo was taken — a process known as geotagging.

Essentially, geotagged photos allow someone with no special training or equipment to determine your exact location right down to the latitude and longitude. Armed with such information, a repressive government or dangerous individual could determine your movements, and establish patterns such as what businesses you frequent and when.

Most users are completely unaware that this feature exists. In many cases, it is the default setting, and often it is not readily apparent whether this function is enabled or not. This means that many smart phone users regularly offer far more information to the public than they realise.

This feature and the opaque way in which it is disguised violates the principles of privacy and data protection outlined in the APC’s Internet Rights Charter. Geotagging and other forms of metadata collection can endanger the individuals who use these devices, and service providers have not been forthcoming about the potential risks.

In addition to its stern warning, icanstalku.com has detailed and user-friendly instructions on how to disable this function on several different mobile devices.

_Photo by Paul Reynolds. Used with permission under Creative Commons license